<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    let str = 'Привет';
    let num = 123;
    let flag = true;
    let txt = 'true';
    console.log(typeof str);
    console.log(typeof num);
    console.log(typeof flag);
    console.log(typeof txt);
</script>
</body>
</html>